Adds quick screenshot method to all SLElement objects

Sources/Classes/UIAutomation/User Interface Elements/SLElement.h

@@ -170,6 +170,29 @@
  */
 - (void)logElement;
 
+#pragma mark - Screenshots
+/// ----------------------------------------
+/// @name Screenshot an element
+/// ----------------------------------------
+
+/**
+ Takes a screenshot of the specified element.
+
+ The rect for the screenshot of the element is automatically provided.
+
+ The image is viewable from the UIAutomation debug log in Instruments.
+
+ When running `subliminal-test` from the command line, the images are also saved
+ as PNGs within the specified output directory.
+
+ @param filename A string to use as the name for the resultant image file.
+
+ @exception `NSInternalInconsistencyException` if `rect` is `CGRectNull` for specified element.
+
+ */
+
+- (void) screenshotWithFilename:(NSString *)filename;
+
 @end
 
 

Sources/Classes/UIAutomation/User Interface Elements/SLElement.m

@@ -27,6 +27,7 @@
 #import "NSObject+SLVisibility.h"
 #import "NSObject+SLAccessibilityDescription.h"
 #import "UIScrollView+SLProgrammaticScrolling.h"
+#import "SLDevice.h"
 
 
 // The real value (set in `+load`) is not a compile-time constant,
@@ -398,4 +399,16 @@ - (void)logElementTree {
     [super logElementTree];
 }
 
+#pragma mark -
+
+- (void) screenshotWithFilename:(NSString *)filename
+{
+    // maybe consider using a timestamp? not sure if it's worth introducing the complexity of NSDateFormatter
+    // The UIAutomation framework automatically appends an integer to screenshots with the same name to prevent overwriting
+    if (!filename) {
+        filename = @"element_screenshot";
+    }
+    [[SLDevice currentDevice] captureScreenshotWithFilename:filename inRect:self.rect];
+}
+
 @end